The first big dust storm of the season fanned out over the weekend to shroudmuch of northern and central China.Skies of Beijing and over northern cities were muddled by orange grit Saturday.

Visibility slipped to a few hundred yards as wind gusts topped 45 mph.

The dust spread quickly southward to the Yangtze River and cities such asShanghai, Wuhan and Nanjing by Sunday.

On Sunday and Monday, haze dulled skies from Hong Kong to Taiwan. Korea andsouthwestern Japan had also seen an interval or two of airborne dust. Forinstance, on late Saturday, the dust storm reached South Korea, where thegovernment hoisted a "Yellow Dust Alert."The trigger for the dust storm actually lay far to the west, over the vast Gobiand other deserts of Mongolia and northwestern China. High winds that sweptover this region, sometimes reaching 60 mph, on Thursday and Friday loftedgreat clouds of dust skyward as well as eastward.

The same storm also shed snow in a swath from Mongolia to northeastern China.

Late winter to mid-spring is the season most prone major dust storms in EastAsia. Storms at this time of year are highly energetic with powerful, gustywinds that easily scoop up the region's fine earth, silt and sand.

Moreover, any winter snow cover disappears at this time leaving desert soilexposed. Sometimes, snow and dust blow together in the same storm leavingbrownish or reddish snow.

Asian dust has been known to traverse the entire Pacific Ocean and reducevisibility in the western United States. This only happens during the mostextreme events. It remains to be seen it this particular event will bring dustto the western United States.

Story by AccuWeather.com Senior Meteorologists Dave Samuhel and Jim Andrews